Fluid pressure brake



Feb. 14, 1939. lays= AIKMAN FLUID PRESSURE BRAKE Filed Jan. 13, 1937 8Sheets-Sheet l *lllllllll INVENTOR BURTON SAIKMAN BY ATIOR NEY Feb. 14,1939. B. s. AIKMAN FLUID PRESSURE BRAKE Filed Jan. 13, 195"! 8Sheets-Sheet 3 Qm oh m 3 $252 0 & Q @ht mu m6 V: we we 93 N? my 3 moSumw 8.528 mb sSmmfi Feb. 14, 1939. B} s A|KMAN 2,147,279

FLUID PRES SURE BRAKE Feb. 14, 1939. B. s. AIKMAN I $147,279

FLUID PRESSURE BRAKE I Filed Jan. 13, 1957 s Sheets-Sheet 5 g INVENTORBURTON $.AIKMAN BY ATTORNEY wmm 0h 3 Ma @Q 0% w? @m Feb. 14, 1939. B. sAIKMAN FLUID PRESSURE BRAKE 'Filed Jan. 13, 1937 8 Sheets-Sheet 6 Feb.14, 1939. B s. AIKMAN 2,147,279

' FLUID PRESSURE BRAKE Filed Jan. l3, 1937 8 Sheets-Sheet 8 M El 7III/1% INVENTOR 45 BURTON S.A||'\MAN ATTORNEY Patented Feb. 14, 1939PATENT OFFICE FLUID PRESSURE BRAKE.

Burton S. Aikman, Wilkinsburg, The Westinghouse Air Brake merding, Pa.,a corporation of Pa., assignor to Company, Wil- Pennsylvania.

Application January '13, 1937, Serial No. 120,378

72 Claims.

This invention relates to fluid pressure brakes and more particularly toa fluid pressure brake equipment of a type which is operative accordingto variations in the pressure of a control pipe for controlling theapplication and release of the brakes on cars of a railway train.

One of the principal objects of the invention is to provide a novelfluid pressure brake equipment of the above mentioned type which iscapable of controlling the application and release of the brakes,particularly on long trains, with promptness, certainty anddependability and further, without causing either harsh run-in orrun-out of the slack in the train; and of materially improving theoperation of the brakes on short trains.

Another object of the invention is to provide'a fluid pressure brakeequipment of the above mentioned type having novel means which for anygiven reduction in brake pipe pressure will produce the desired brakecylinder pressure regardless of the brake cylinder volume or travel ofthe brake cylinder piston.

Another object of the invention is to provide a fluid pressure brakeequipment having novel means for maintaining the brake cylinder pressureagainst leakage.

Another object of the invention is to provide a fluid pressure brakeequipment of the above mentioned type having novel means for effecting aretarded release of the brakes and an accelerated recharge of the brakepipe.

Another object of the invention is to provide a fluid pressure brakeequipment in which there is embodied a tilting motor adapted to becontrolled by transferring or shifting weight or ballast, such forinstance as mercury, from one position on the motor to another or byincreasing or decreasing the effectiveness of the weight in any othermanner for controlling the application and release of the brakes.

Another object of the invention is to provide a fluid pressure brakeequipment having novel means for facilitating the release of the brakes.

Another object of the invention is to provide a fluid pressure brakeequipment having novel means for propagating a quick service reductionin brake pipe pressure throughout the length of the train, and a furtherfeature resides in the utilization of such means to insure quick actionin effecting an emergency application of the brakes.

Another object of the invention is to provide a fluid pressure brakeequipment having novel means for controlling the rate of build up ofbrake cylinder pressure in effecting either a service or an emergencyapplication of the brakes in such a manner as to prevent slack in thetrain from running in and closing so harshly as to cause excessiveshock.

Another object of the invention is to provide a fluid pressure brakeequipment having the above improved novel features, which will functionsatisfactorily in a mixed train having some of the cars equipped with mynovel fluid pressure brake equipment, and other cars equipped with theold type of fluid pressure brake equipment such as the equipmentembodying the K type of brake controlling valve device, and furtherimproves the operation of the old equipment.

Another object of the invention is to provide a fluid pressure brakeequipment in which the cost of construction and maintaining is reducedto a minimum.

Further object of the invention is to provide a fluid pressure brakeequipment in which the usual pistons employed to effect the supply offluid under pressure to and the release of fluid under pressure from thebrake cylinder and-the attendant undesired but unavoidable leakage offluid is eliminated.

In general, the present invention contemplates the attainment of theforegoing and other objects and advantages and the elimination orminimization of certain inherent difliculties and disadvantages of fluidpressure brake equipment heretofore in use, by a mechanism whichresponds to variations in brake pipe pressure but which in constructionand principle of operation difiers materially from that of fluidpressure brake equipment at present and heretofore employed.

Additional objects and advantages will appear in the following moredetailed description of the invention.

In the accompanying drawings, Fig. l is a diagrammatic view showing atrain consisting of a locomotive, tender and two cars, the tender andeach car being equipped with a fluid pressure brake equipmentconstructed in accordance with the invention; Fig. 2 is a diagrammaticview, mainly in section, of a portion of the locomotive brake equipment;Fig. 3 is a fragmentary plan view of the brake valve device, a portionof the handle being broken away to more clearly illustrate certaindetails, and the several controlling 50 positions of the handle; Fig. 4is a fragmentary sectional View of the emergency valve portion of thebrake valve device, the emergency valve being shown in emergencyposition; Fig. 5 is a diagrammatic view, mainly in longitudinalsecervoir 1, a brake tion, of the fluid pressure brake equipmentconstructed in accordance with the invention, the several parts of theequipment being shown in normal release position; Figs. 6, '1, 8 and 9are sectional views similar to Fig. 5 but showing the equipment indifferent brake controlling positions, Fig. 6 showing the equipment inservice application position, Fig. '1 showing the equipment in servicelap position, Fig. 8 showing the equipment in retarded release positionand Fig. 9 showing the equipment in emergency position; Fig. 10 is anend elevational view, partly in section, of the equipment, the sectionalportions being viewed on the line 8-8 of Fig. '7; Fig. 11 is afragmentary sectional view of the equipment with the release delay valvemechanism removed; Fig. 12 is a fragmentary sectional view illustratingamodification of the invention; and Fig. 13 is a fragmentary sectionalview illustrating another modification of the invention.

In Fig. 1 of the drawings a fluid pressure brake equipment for a railwaytrain consisting of a locomotive, tender and two cars isdiagrammatically illustrated and, as shown in this figure and also inFig. 2, the locomotive equipment may comprise a brake pipe l, a mainreservoir 2, a brake valve device 3, a feed valve device 4 and a quickaction vent valve device 5 and, although not shown, may comprise theBET, 8ET or any other desired distributing valve mechanism and mayfurther comprise the usual independent brake valve device forindependently controlling the locomotive brake. Since the locomotivedistributing valve mechanism and independent brake valve device have noparticular bearing on the present invention it is deemed unnecessary toshow or describe them.

The tender and car fluid pressure brake equipment may comprise a brakepipe 6, a supply rescylinder 8 and a brake controlling mechanism 9,which mechanism may comprise a brake controlling device In, with whichthere is associated a brake application valve device 12, a chargingcontrol valve device 13, a brake cylinder pressure build-up controlvalve device 14, a quick service valve device 15, a quick action ventvalve device 16, a brake cylinder release delay valve device 11, and abrake cylinder release valve device 18. V

The brake controlling device Ill comprises a pipe bracket 19 having acasing portion 20 which has associated therewith the brake cylinderbuildup control valve device 14, quick service valve device 15, quickaction'vent valve device 16, and brake cylinder release valve devicel8,'said casing having a base or flange 21 which as shown in Fig. l isadapted to be rigidly secured by means of bolts 22 to a relatively fixedpart 23 of the vehicle. The left hand end of the pipe bracket isprovided with a clamping face to which is removably clamped the brakecylinder release delay valve device I1, there being a gasket interposedbetween the clamping face of the bracket and device.v Extendingdownwardly from the casing 20 and preferably integral therewith arelaterally spaced lugs or legs 25, 26 between which is disposed atiltable beam 21 which is secured, by means of a key 28, to a rockableshaft 29 mounted in ball bearings 33 and 3! carried by the lower ends ofthe lugs 25 and 26 respectively. The left hand end of the shaftterminates within a chamber 32 formed in the lug 25, there being anannular packing 33 contained in this chamber and secured to the lugwhich is adapted to engage the shaft to prevent leakage of fluid underpressure from the chamber. The lug 26 carries the casing of theapplication valve device 12 and secured to this casing is the casing ofthe charging control valve device 13, there being a gasket 35 interposedbetween the casings. An end wall 36 of the casing of the chargingcontrol valve device separates chambers 31 and 38 of the valve devices12 and 13, respectively. As shown in Fig. 10 the valve devices 12 and 13are arranged at one side of the beam 21, but in order to more clearlyillustrate the details of the equipment the showing of the shaft anddevices has been distorted in Figs. 5 to 9 inclusive.

The right hand end of the shaft 29 extends beyond the ball bearing 3|,through chamber 31 and through an opening in the end wall 35 of thecasing of the valve device I3 and terminates within the chamber 38.Secured to the opposite sides of the end wall 36 are annular packings 39which are adapted to engage the shaft to prevent leakage of fluid underpressure between the chambers, and secured to the lug 26 there is asimilar packing which is adapted to prevent leakage of fluid underpressure from the chamber 31 to the atmosphere by way of the ballbearing 31.

Contained in the chamber 31 and rigidly secured to the shaft 29 is anarm 49 which is adapted to control the operation of an application valve41 hereinafter more fully described.

Contained in the chamber 38 and rigidly secured to the shaft 29 is anarm 42 which is adapted to control the operation of a charging controlvalve 43 hereinafter more fully described.

The tiltable beam 21 may comprise a casing in which there is provided acontrol chamber 44, a chamber 45, and a chamber 46, a well 41 and a well48. The chambers 45 and 46 are arranged above the axis of the shaft 29and at opposite ends of the beam equi-distant from the shaft. The wells41 and 48, are arranged below and at opposite sides of the axis of theshaft 29, the space between the wells being considerably less than thespace between the chambers 45 and 46. The control chamber 44 may bearranged above the axis of the shaft 29 and between the chambers 45 and46, respectively.

The chamber 45 is constantly connected, through a passage 48 in thecasing, a passage 50 in the shaft 29 and a passage 5| in the arm 42, tothe operating face of the arm 42, the passage 51 being flared outwardlyat the face of the arm to form a valve seat 52. This chamber 45 isconnected through a downwardly extending passage 53 of relatively largeflow area to the lower end of the well 41, which well contains a supplyof mercury 54 or any other suitable weighting material which is freelymovable or displaceable at all times from one place to another, themercury being also contained in the passage 53 to a level correspondingto that of the mercury in well 41. The supply of mercury is notsufficient to flll the well 41 and the upper end of the well isconnected to the control chamber 44 through a passage 55 provided in awall 55 which separates the wells and control chamber. Contained in thewell 41 and floating on top of the mercury 54 is a fluid pressure flowcontrol member 51 which, as will hereinafter more fully appear, isadapted to control the flow of fluid from the control chamber to thebrake pipe in effecting an emergency application of the brakes. Thismember does not have a close fit with the walls of the well 41, therebeing suflicient clearance between the edge of the member and the wallto permit the free flow of fluid under pressure from the under-side ofthe plate to the upper end of the well when charging or re-charging theequipment as will hereinafter more fully appear. This member is providedwith a central opening or port 58 of small flow area which, when themercury in well 47 is forced to a low level in effecting an emergencyapplication of the brakes and the member seats on a seat rib 59 carriedby the casing, is adapted to restrict the flow of fluid from the controlchamber to the chamber 45 and consequently to the brake pipe as willhereinafter more fully appear. The well 48 is constantly connected to abrake cylinder passage 60 in the casing 20 by way of a passage 6! in thecasing of the beam, a passage 62 in the shaft 29, chamber 32 in the arm25 and casing 20 and a passage 63 in said arm and casing 20. Above thejunction of the passage Bl with the well 48 a wall 64 is provided whichdefines the upper end of the well 48, which wall is provided with adownwardly depending tubular portion 65 which establishes communicationfrom the bottom of the well to a passage 96 which leads upwardly andwhich at its upper end is constantly connected to the chamber 46. Thiswell 48 is provided with a supply of mercury which is separate from thesupply in well 4'! but the amount of mercury is insufficient tocompletely fill the well, the level of the mercury being kept below thejunction of the passage 6| with the well so that, as will hereinafterappear, fluid under pressure from the brake cylinder passage 59 andadmitted to the chamber through passage 5! will act over a large portionof the area of the upper surface of the mercury. The amount of mercurycontained in this well 48 is preferably greater than that contained inwell 47 so that the beam will, with the brakes released, assume thetilted position in which it is shown in Fig. 5. The control reservoir 44is connected to the supply reservoir '1 by Way of a passage 68 in thecasing of the beam, passage 69 in the shaft 29, and a passage 10 in thecasings of the application valve device l2 and charging control valvedevice l3, past a ball check valve H, ball check valve chamber '52, achoke 13, valve chamber 14 containing the application valve 4|, andpassage and pipe '15, as shown in Figs. 5 to 9 inclusive.

Extending into the control chamber M and having screw-threadedconnection with an upper wall 16 of the beam casing is a spring case 11in which there is mounted a vent valve 18 which is adapted to cooperatewith a valve seat on the cage to control the release of fluid underpressure from the control chamber to the atmosphere. This valve isprovided with a fluted stem l9 which extends through the vent passage inthe cage to a point above the wall 16 of the beam, and at its end is incontact with an operating arm 89 which extends in a directionlongitudinally of the beam and which at one end is pivotally connectedby means of a pin 8! to a bracket 82 preferably integral with the wall16 and located adjacent the right hand end of the beam. This bracketalso serves as a stop memberwhich is adapted to be engaged by a stop 63depending downwardly from the casing 26, to limit the releasing movementof the beam as will hereinafter more fully appear. The valve 18 isnormally maintained closed by means of a spring 84 carried by the cage17.

- The operating arm 80 is provided at its outer end with an upwardlyextending portion 85 and located above this portion 85 is an arm 86which, at its upper end, is rockably mounted on a pin 81 carried by abracket 88 preferably integral with the casing 20 and extendingdownwardly therefrom. The lower end of the arm is provided with a weight89 which is adapted to operatively engage the portion 85 of the arm 80.The pivoted end of the arm is prow'ded with a lug 95 which is adapted tobe engaged by a stationary stop 9! carried by the bracket, to limitmovement of the arm in a counterclockwise direotion for reasons whichwill be hereinafter fully described.

The build-up control valve device M, in the present embodiment of theinvention, is for the purpose of controlling the rate of increase inbrake cylinder pressure in effecting either a service or an emergencyapplication of the brakes, the operation of the device being such as topermit an initial inshot of fluid under pressure to the brake cylinderto apply the brakes with a light but sufficient force to start the slackin the train to gather or close, to then restrict the rate of flow offluid under pressure to the brake cylinder to insure the gentlegathering or closing of the train slack and finally to provide a finalrapid inshot of fluid under pressure to the brake cylinders to effectthe desired degree of braking. This device comprises a piston 92 havingat one side a chamber 93 which is connected through a passage 94 to theatmosphere, and having at the other side a chamber 95 which is connectedto the brake cylinder passage St and which is connected to the chamber36 of the application valve device !2 by Way of a passage 55 ofrelatively large flow area, a chamber li'i and a passage and pipe 98.The piston 92 is provided with a stem 99 which extends through thepassage 96 into the chamber in and at its end is normally engaged by theright hand end wall of the chamber 97, a coil spring it!!! contained inthe chamber 83 and acting through the medium of the piston 92maintaining the stem in this position. The piston stem 99 intermediateits ends is provided with a circular imperforate disc Iii! which has adiameter slightly less than that of the passage 95 and is adapted to bemoved through this passage. It will be noted that with the piston andpiston stem in their normal position, the disc I! is wholly contained inthe chamber 91 so that it does not serve to restrict the flow of fluidto the passage 96.

The quick action vent valve device l6 may comprise a piston I02 at oneside of which is a piston chamber I03 to which fluid is adapted to flowby way of a passage I04 when, as will hereinafter be fully described,either a service or an emergency application of the brakes is initiated.The piston chamber is connected to a passage I which leads to theatmosphere and which is adapted to be maintained open to the atmos pherein controlling a service application of the brakes and to be closed uponthe initiation of an emergency application of the brakes, the quickservice valve device l5 controlling communication through the passage aswill hereinafter appear. At the other side of the piston is a chamberH36 which is connected through a passage Ill! to the atmosphere. Thepiston I02 is operatively connected by a fluted stem N38 to a brake pipevent valve I09 contained in a chamber llll to which the brake pipe 6 isconnected by way of a branch pipe l l l. The vent valve N19 is operativeto control communication from the valve chamber Hi! to the atmosphericchamber N36 and is normally maintained in its closed position by theaction of a coil spring I 12 contained in the chamber III). The ventvalve chamber III! is connected through a passage and pipe H3 to thechamber 38 of the charging control valve device I3 and is also connectedto a passage H4 which leads to the brake cylinder release delay valvedevice I1.

The quick service valve device I5 is for the purpose of venting fluidunder pressure from the brake pipe to insure the propagation of quickservice action from car to car throughout the length of the train andmay comprise a vent valve H5 which is contained in a. chamber H5connected to the brake pipe passage H4 through the passage in a chokeplug i ll. This vent valve is adapted to control communication from thechamber H6 to the passage I84 and is normally maintained in itscommunication closing position by the action of a coil spring H8contained in the chamber. The valve is provided with a stem H9 whichextends to the exterior of the casing 20 and which at its outer end isprovided with a valve I2!) which, when an emer gency application or" thebrakes is initiated, is adapted to be moved upwardly into sealingengagement with the casing to cut off communication from the passage I55to the atmosphere and thereby condition the quick action vent valvedevice for operation to vent fluid under pressure from the brake pipe.

The operation of the quick service valve device I5 is adapted to becontrolled by the operation of a bell crank lever I2I which is pivotallymounted on a pin I22 carried by laterally spaced brackets I23 to rock indirections longitudinally of the tiltable beam 21, which brackets extenddownwardly from and are preferably integral with the casing 20. Thelever I2! is provided with a substantially vertically disposed arm I24which at its lower end is provided with a rounded portion I25 whichextends between and is operatively engaged by spaced driving lugs I28iiitegrally connected with and extending upwardly from the wall 18 ofthe beam, which logs are arranged one on each side of a vertical linepassing through the axis of the shaft 23. The other arm, I21, of thelever, extends in a direction longitudinally of the beam and under thecut-oil valve I20, the arm being adapted to engage the valve and causeit to; seat only when an emergency application of the brakes isinitiated.

The brake cylinder release delay valve device I1 is for the purpose ofdelaying the release of the brakes until the brake pipe pressure hasbeen increased a predetermined degree above brake cylinder pressure orin other words until the brake pipe pressure has been increasedsufficiently to cause the usual types of triple valve devices to startto move towards release position against the opposing reduced auxiliaryreservoir pressure, thus contributing materially to the synchronizationof the brakes on the cars of a mixed train in which some of the cars maybe equipped with the usual type of brake apparatus and others may beequipped with the apparatus herein described. This delay valve devicemay comprise a flexible diaphragm I28 having at one side a chamber I29connected to the brake pipe passage H4 and having at the other side achamber I38 which is connected to the passage 59 and which is alsoconnected through a passage and pipe I3I to the brake cylinder 8.Secured to the diaphragm is a follower i32 having a fluted stem I33adapted to operate a delay valve I34 contained in a chamber I35connected to a release passage I36 leading to the brake cylinder releasevalve device I8. Contained in the chamber I35 is a coil spring I31 whichtends to urge the delay valve I34 toward its communication closingposition.

The brake cylinder release valve device I8 is 5 for the purpose ofclosing the release communication irom the brake cylinder in initiatingan application of the brakes and to effect a release of fluid underpressure from the brake cylinder at either the usual rate or a retardedrate according to the operation of the bell crank lever I2I by thetiltable beam, and may comprise connected oppositely seating valves I40and MI which are contained in a chamber I42 connected to the releasepassage I36. The valve I40 is adapted to engage an annular seat rib I43encircling the passage I36 when, as will hereinafter be described, thetiltable beam moves to retarded release position. The seat rib I43, ashort distance rearwardly from its seat, is provided with a flowrestricted passage I44 which is in communication with both the passageI36 and chamber I42.

The valve MI is adapted to control communication from the chamber I42 toa release passage I45 connected to a pipe I48 leading to the usualretainer valve device I41, as shown in Fig. 1. This valve is providedwith a fluted stem I48 which is engaged at its end by the inner end of aplunger I49 which extends through the casing 23 and which at its outerend is operatively engaged by the arm I24 of the bell crank lever I2I.The plunger I49 adjacent its outer end and exteriorly of the casing 20is provided with a spring seat I andinterposed between and engaging thisspring seat and an exterior surface of the casing 23 is a heavy coilspring I5I which is adapted to be compressed only when the tiltable beamis being moved from release position to retarded release position. Thepurpose of this spring, as 4 will hereinafter more fully appear, is toreturn the tiltable beam from its retarded release position to itsnormal release position. Contained in the valve chamber I42 andinterposed between and operatively engaging the release valve assemblyis I a spring I52 which tends to urge the valve assembly towards theright hand or seating position of the valve I4I.

With further reference to the application valve device I2, the valve Mis adapted to control com munication between the chambers 14 and 31 andis normally maintained seated, by the action of a coil spring I53contained in chamber 14, said valve having a fluted stem whch extendsinto the chamber and which at its end is adapted to be operativelyengaged by the arm 40.

With further reference to the charging control valve device I3, thevalve 43 is contained in the chamber I54 to which the supply reservoirpassage 15 is connected by way of a passage and pipe 6 i55, the passagein a choke plug I56, passage I51 and past a ball check valve I58.Contained in the chamber I54 is a coil spring I59 which at all timestends to urge the valve 43 to its closed position. This valve isprovided with a fluted stem ifill whch extends into the chamber 38 andthe end of this stem is in the form of a valve IBI on which the valveseat 52 of the arm 42 is adapted to seat.

The brake valve device 3 of the portion of the locomotive brakeequipment which is shown in Figs. 1, 2 and 3 of the drawings is of theselflapping type and may comprise a body casing I1I and a cap I12 whichis removably secured to the I casing by any suitable means. Clampedbetween the casing and shaft is a flexible diaphragm I13 having at oneside a chamber I'I4 which is connected through a port I15 to theatmosphere, and having at the other side a chamber I I6 which isconnected through a passage and pipe I" to the locomotive brake pipe I.

Contained in the chamber H4 is a follower I18 having a stem I19projecting upwardly from one side thereof and having a short stem I88projecting downwardly from the other side and through a central openingprovided in the diaphragm. The stem I79 is round in cross-section andextends through a central opening in a rotatable and vertically movablecontrol member I BI having screw-threaded connection with the upper endof the cap I12 to efiect the vertical movement of the member when themember is rotated. This control member is provided with a pinion I82which meshes with a gear segment I99 carried by a rotatable handle I84having at one end a hand piece I85 adapted to be grasped by theoperator, and having at its other end a downwardly extending portion I86which is round in cross-section and which is journaled in a laterallyprojecting portion I91 of the shaft.

The lower end of the journal portion I86 of the handle I84 projectsthrough the portion I8'I of the cap and is provided with a downwardlydepending cross-lug 588 which extends into a corresponding groove I89 inthe upper end of the stem I99of a rotatable emergency valve I9Icontained in a chamber I92 in the casing III, said stem being journaledin the casing in axial alignment with the porton I86 of the handle.

Contained the chamber 57 and surrounding the stem H9 is an annular ballbearing spring seat I93 which rests on the upper surface of the follower!?8 and which is slidably guided both vertically and laterally by anannular wall I94 of the cap as shown in Fig. 2. Interposed between andoperatively engaging the spring seat and the inner end of the controlmember I 8| is a control spring I95. It will here be noted that the ballbearing spring seat I93 provides for the free rotation of the controlspring so that the tendency of the spring to wind up when the controlmember I9I is rotated is so reduced to a minimum that the danger of thespring acting to return the handle from any control position to which ithas been moved is eliminated.

The upper end portion of the stem I19 projects above the pinion I82 andis provided with transversely extending pin I96 which may project fromboth sides of the stem and which is adapted to be engaged by theadjacent end face of the pinion when, as will hereinafter fully appear,the handle I8 is moved to emergency position. In all other positions theend face of the pinion does not engage the pin.

Contained in the chamber I19 and slidably guided by the casing I II is atubular sleeve I9! which has screw-threaded connection at is upper endwith the stem I89 of the follower I78, said sleeve clamping the flexiblediaphragm to the follower and forming an extension of the stem I139. Theextension I9? and follower are provided with a passage I98 which leadsto the chamber 5'54. Formed on the lower end of the sleeve Isl andencircling the passage I99 is a valve seat on which an exhaust valve I99is adapted to seat to cut off communication from the chamber I76 to theexhaust passage I98. This valve is secured to the end of the fluted stem299 of an oppositely seating pilot supply valve 29! contained in achamber 292 which is connected through a pipe 293 to the feed or supplyvalve device 4, said valve 29I being at all times urged toward its seatby the action of a light coil spring 294.

As shown in Fig. 3, the brake valve handle I84 is movable through anapplication and release Zone, one end of said zone being runningposition and the other being emergency application position and ifdesired the handle may be readily removed from the cap in runningposition as shown in Fig. 2. In this connection it will be noted thatthe journaled portion I86 of the handle is provided with acircumferential groove 295 for the reception of a securing pin 296 whichhas a driven fit with the portion I8! of the cap, the pin serving tolock the handle to the cap in every position except running position. Inthis latter position of the handle a vertical groove 29'! in the portionI86 of the handle and opening into the groove 295 is directly beneaththe pin and is adapted to permit the lower end of the handle portion I89to be raised out of locking engagement with the securing pin. Due to theseparable connection between the lower end of the handle portion I86 andthe upper end of the emergency valve stem I99, said stem is notinterfered with upon the removal of the handle or in case repairs arenecessary upon the removal or replacement of the cap and handle as aunit.

The chamber I92 containing the emergency valve I 9I is connected througha passage and pipe 298 and a main reservoir pipe 299 to the mainreservoir 2.

The feed or supply valve device 4 is provided for the purpose ofcontrolling the supply of fluid under pressure from the main reservoir 2to the brake pipe and is operative in accordance with the automaticoperation of the pilot supply valve 29I of the brake valve device aswill hereinafter more fully appear in the description of the operationof the apparatus, and may comprise a casing having a chamber 2 I 9connected through pipe 293 to the pilot supply valve chamber 292 of thebrake valve device. Contained in this chamber 2I9 is a piston H I havinga stem 2I2 which is adapted to operate a slide valve 2 I3 contained in achamber 2 I4 connected to the main reservoir pipe 299, said piston andslide valve being operative to control communication from the valvechamber 2 I 4 to the brake pipe I. Contained in the chamber 2I9 andinterposed between and operatively engaging the piston and the casing isa coil spring 2I5 which, when the fluid pressure acting on oppositesides of the piston are substantially equal to each other, is adapted tomaintain the piston and slide valve in their cut-on position as shown inFig. 2.

The vent valve device 5 comprises a casing having a chamber 2I6connected to a passage and pipe 2I'I leading to the seat of theemergency valve I9I and containing a piston 2I8 having a fluted stem 2I9which is adapted to control the operation of a vent Valve 229 containedin a chamber 22I connected through a passage and pipe 222 to the brakepipe i, said valve being adapted to control communication from thechamber 22! and brake pipe to a passage 223 leading to the atmosphere.The vent valve is normally maintained in its closed position as shown inFig. 2 by the action of a coil spring 224 contained in chamber 22I.

Initial charging of the train brake equipment With the brake valvehandle I84 in running position as shown in Fig. 3 and the locomotivefluid pressure brake equipment depleted of fluid under pressure, thebrake valve control spring I95 acts through the medium of the ballbearing I93, follower I18, follower stem I80, member I91 and exhaustvalve I99 to maintain the pilot valve 20I unseated against the opposingpressure of the spring 204, thus maintaining open the communication fromthe valve chamber 202 and thereby the piston chamber 2 I of the feedvalve device to the diaphragm chamber I16, passage and pipe I11 andbrake pipe I. Since the chamber 2 I4 and 2I0 of the feed valve deviceare at atmospheric pressure the spring 2I5 acts to hold the piston 2 IIand thereby the slide valve H3 in its cut-off position.

Fluid under pressure now supplied to the main reservoir 2 in the usualmanner, flows therefrom through pipe and passage 209 to the slide valvechamber 2I4 of the feed valve device and causes the feed valve piston 2Hand thereby the slide valve 2 I3 to move in a direction toward the righthand against the opposing pressure of the spring 2 I5 to their cut-inposition, in which fluid under pressure flows from the valve chamber 2I4and connected main reservoir to the brake pipe by way of a port 225 inthe slide valve and a passage 226. From the brake pipe I fluid underpressure flows through the brake pipe branch pipe and passage I11 to thediaphragm chamber I16 of the brake valve device and from the diaphragmchamber flows past the unseated pilot valve 2!" to the piston chamber2!!! of the feed valve device by way of pilot valve chamber 202 and pipe293. It will here be noted that the valve I99 is maintained in itsclosed position, so that there can be no escape of fluid under pressurefrom the chamber I16 and consequently from the brake pipe by way of theatmospheric passage I98.

Now when the brake pipe has been charged to the pressure which it isdesired to carry, say for instance to seventy pounds, fluid in thechamber I15, which is at brake pipe pressure, causes the diaphragm I13to flex upwardly against the opposing pressure of the control springI95, the follower I19 and member I91 being moved upwardly by thediaphragm. As the member I91 thus moves, the spring 204 acts to move thevalve 20l to its closed position as shown in Fig. 2, and as the valve isseating, the pressure of fluid in chamber 2 I9 of the feed valve devicewill be increased sufiiciently by the flow of fluid fromthe valvechamber 2I4 by way of a small leakage passage 221 in the feed valvepiston 2 as to permit the spring 2I5 to move the piston and thereby theslide valve 2I3 to their cut-out position as shown in Fig. 2 in whichposition, the flow of fluid from the main reservoir to the brake pipe iscut oil. It will here be understood that as the valve 20I is seating theseveral parts of the feed valve device move to their cut-off position sothat the upward flexing diaphragm will seat before the valve seat of themember I91 can move away from the exhaust valve I99, thus communicationbetween the chamber I16 and atmopsheric passage I98 is maintainedclosed.

Fluid under pressure supplied to the brake pipe I of the locomotiveflows to the connected brake pipe 6 of the tender and cars of the trainas will be apparent from Fig. 1 of the drawings.

Fluid under pressure flows from the brake pipe 6 on each vehicle throughbranch pipe III, quick action valve chamber H0, and passage II4 to thediaphragm chamber I29 of the brake cylinder release delay valve deviceI1 and causes the diaphragm I28 to flex inwardly and unseat the delayvalve I34, thus establishing communication from chamber I30 to therelease passage I36, which, as will hereinafter more fully appear is incommunication with the atmosphere by way of release valve chamber I42,past the normally unseated release valve I4I, passage I45, pipe I46 andretainer valve device I41. The tender equipment does not include aretaining valve device so that the passage I45 of such equipment leadsdirectly to the atmosphere. The passage I3I leading from the brakecylinder is in constant open communication with the chamber I30 so thatthe brake cylinder is normally at atmospheric pressure. The brakecylinder supply passage 60 being in communication with the passage 98 byway of piston chamber 95, port 96, chamber 91 and passage -98 and withthe chamber I30, the chamber 31 of the application valve device I2 isnormally at atmospheric pressure.

From the quick action vent valve chamber IIO fluid under pressure flowsthrough passage and pipe H3 to chamber 38 of the charging control valvedevice I3 and from thence flows to the chamber 45 in the tiltable beam21 by way of the open valve I6I, passage 5| in the arm 42 of thecharging control valve device, passage 50 in the shaft 29, and passage'49 in the beam.

The chamber 45 being in constant open communication with the passage 53,fluid under pressure acting on the surface of the mercury in thispassage causes the mercury to be displaced to the well 41 until thelevel of the mercury in the passage is lowered to the junction point 228of the passage with the well. With the mercury in the passage at thislevel, fluid under pressure flows or bubbles through the mercury in thewell and past the member 51 to that portion of the well which is abovethe member and from thence flows through passage 55 to the controlchamber 44.

From the control chamber 44 fluid under pressure flows to the supplyreservoir 1 by way of passage 69 in the beam, passage 59 in the shaft29, passage 10, past ball check valve 1! mounted in the casing of theapplication valve device I2, ball check valve chamber 12, the flowrestricting passage in the choke 13, valve chamber 14 and passage andpipe 15.

Now when the pressure of fluid in control chamber 44 is increased tosubstantially that of the fluid in passage 53, the mercury which hasbeen displaced from passage 53 will flow back from the well 41 to thepassage. It will here be understood that the pressure of fluid in thecontrol chamber, when the chamber is fully charged, will be less thanthat of the pressure of fluid in the brake pipe by an amount equal tothat required to displace the column of mercury in the passage.Obviously this difference in pressures will be so slight as to benegligible. Due to the brake pipe pressure present in passage 53, whenthe equipment is fully charged, being slightly greater than that of thecontrol chamber, the mercury in the passage will not attain its naturallevel as shown in Fig. 5, but this is immaterial and will have noappreciable effect upon the operation of the equipment.

With the beam 21 in release position as shown in Fig. 5, the spring I5Iacting through the medium of the plunger I49, bell crank lever I2I andlug 36 on the beam, acts to stabilize the beam against unintentionaltilting back and forth between release and retarded release position,thus preventing undue wear of the several movable parts of the apparatuswhich are associated with the beam.

From the foregoing description of the operation 7 that the brakecylinder is connected to the atmosphere.

Service application When it is desired to effect a full serviceapplication of the brakes, the operator moves the brake valve handle H34from running position and through the application and release zone tofull service position. Upon such movement of the handle the toothsegment I83 thereof meshing with the teeth on the pinion I82 causes thepinion and thereby the screw-threaded portion of the control member [8|to rotate in a clockwise direction relative to the stem H9 of thefollower I18, and as the member is thus rotated the screw threads on themember and those on the casing cooperate to move the member upwardlyrelative to the follower stem H9. With the handle in full serviceposition the upper end of the pinion does not operatively engage the pinlet carried by the stem Iiil, therefore the member as it is movedupwardly does not effect upward movement of the stem.

As the member [3! is moving upwardly it permits the control spring L95to expand, thus reducing the pressure of the spring and therebypermitting fluid at full brake pipe pressure present in chamber I16 toflex the diaphragm H3 upwardly, the diaphragm upon such movementshifting the follower I18, follower stems i'i'B and I and follower stemextension is] in the same direction against the opposing adjustedpressure of the spring I95. Since, with the pilot valve 20! seated, thevalve I98 cannot move upwardly with the stem extension I97; the valveseat carried by the extension is moved away from thevalve I99 so thatfluid under pressure is now vented from the brake pipe to the atmosphereby way of brake pipe branch pipe and passage ill, chamber I16, past thevalve 599, passage 5S8, chamber I 14 and passage H5, thus initiating areduction in brake pipe pressure. Now when the brake pipe pressure hasbeen reduced slightly below the opposing pressure of the sprin 995, saidspring acts to move the diaphragm and thereby the diaphragm stemextension downwardly, the valve seat on the stem extension engaging thevalve ISG to cut off the flow of fluid from the chamber I16 andconsequently from the brake pipe to the atmosphere. With the exhaustflow of fluid from the chamber H5 and the brake pipe thus cut off, thedownward flexing of the diaphragm ceases, so that the pilot valve 211iremains seated.

The brake pipes of the locomotive tender and cars are connected togetherin the usual manner and, in effect, form a continuous brake pipe fromend to end of the train, so that the reduction in brake pipe pressureefiected in the manner just described will be effective on each car ofthe train.

Since, as hereinbeiore described, the brake pipe is in communicationwith the chamber 35 of the tiltable beam 2'! by way of pipe i l, quickaction vent valve chamber Ill passage and pipe H3, chamber 38 of thecharging control valve device l3, passage 5| in the arm 42 and passages53 and 49, the pressure of fluid in this chamber reduces with brake pipepressure.

As the pressure of fluid in chahber ts is reducing with brake pipepressure, the pressure of fluid in the control chamber 44 and unoccupiedportion of the mercury well 41 forces mercury from the well andconnected passage 53 upwardly into chamber 45. Since the chamber A5 islocated some distance to the right of the well 41, the weight of themercury displaced into the cham ber 65 causes the beam, shaft 29 andarms 5! and 42 secured to the shaft to rock or tilt in a clockwisedirection from their normal release position as shown in Fig. 5 to theirservice position as shown in Fig. 6.

As the beam is being thus tilted or rocked from normal release position,the lugs I25 of the beam cause the bell crank lever IZI to rock in acounterclockwise direction about the pin i22. As the lever is thusmoving, the arm I2 8 thereof moves out of supporting relationship withthe plunger I49 of the release valve device and permits the spring lfilto expand to its free length and, in so expanding, moves the plunger outof supporting relationship with the release valve I ii so that thespring 952 is permitted to move the release valve to its closed positionas shown in Fig. 6. At substantially the same time as the release valveMI seats the arm l2! of the bell crank lever engages the valve I20 ofthe quick service valve device I5 and through the medium of this valveand valve stem H9 moves the qm ck service vent valve H5 upwardly fromits seat against the opposing pressure of the spring H8.

With the quick service vent valve H5 unseated fluid under pressure islocally vented from the brake pipe to theatmosphere by way of branchpipe I! l, quick action valve chamber I i8, passage M4, the flowrestricting passage in the choke plug Iii, quick service vent valvechamber I I6, past the open quick service vent valve iiii, passage EM,quick action piston chamber E03 and passage N35. The flow areas of thepassage in the choke plug ill and the passage WE are so proportioned,with respect to each other, that the flow of fluid under pressure fromthe brake pipe to the quick action piston chamber I 63 is not permittedto build up a sufiicient fluid pressure in this chamber to move thequick action piston i 62 toward the right hand and cause an undesiredemergency application. The flow area of the passage in the choke plug iI? is such that enough fluid pressure is vented from the brake pipe tocause a definite local reduction in brake pipe pressure, which reductionis transmitted in like manner to the next tiltable beam and in turn tothe next, thus increasing the rapidity with which the brake pipereduction travels throughout the length of the train. This quick serviceventing of fluid under pressurue from the brake pipe continues as longas the tiltable beam is in service position.

After the quick service vent valve I I5 has been unseated the continuedrocking of the beam and thereby the shaft 29 to service position causesthe arm '39 carried by the shaft 29 to engage the stem of the supplyvalve M of the application valve device i2 and move the valve M from itsseat against the opposing pressure of the spring I53. Fluid underpressure now flows from. the supply reservoir 1 to the brake cylinder byWay of pipe and passage '55, supply valve chamber'l i of the applicationvalve device 52, past the open supply valve lL'chamber 37, passage andpipe 98, chamher 9'! in the brake cylinder build up control valve deviceit, passage at, piston chamber 95, passage 6t, diaphragm chamber ltd ofthe brake cylinder release delay valve device I1, and passage and pipel3! It will here be noted that due to the displacement of the mercury inwell 41 the pressure of fluid in control chamber 44 is reduced by theexpansion of the fluid into the space formerly occupied by the mercuryto substantially brake pipe pressure.

Now when the pressure of fluid in piston chamber of the brake cylinderbuild up control valve device I4 has been increased a predeterminedamount, for instance to around fifteen pounds, the piston 92 starts tomove in a direction toward the left hand against the opposing pressureof the spring I09, and as it thus moves it acts, through the medium ofthe piston stem 99, to shift the imperfora-te disc lGI into the passage96 where it serves to restrict the passage 96 and thereby retard therate of flow of fluid to the brake cylinder. As the pressure of fluid inthe piston chamber 95 continues to increase the piston continues to movethe disc Iii! through the passage 95 until the disc is clear of thepassage, at which time the flow of fluid through the passage 96 to thebrake cylinder will again be at a rapid rate. This latter rate of flowof fluid to the brake cylinder continues until the desired brakeapplication has been obtained. It will here be noted that the build upof brake cylinder pressure is in three stages; first there will be aninshot of fluid to the brake cylinder which will increase brake cylinderpressure to produce a light application of the brakes sufficient tostart the slack in the train to run in or gather gently, then there willbe a slow increase in brake cylinder pressure while the slack in thetrain is gathering or closing, and finally there will be a rapid inshotof fluid to the brake cylinder to effect a rapid increase in brakecylinder pressure after the slack in the train has run in or gathered.By reason of this controlled build up of brake cylinder pressure harshrun in or closing of the train slack is prevented.

Since the diaphragm chamber I29 of the brake cylinder release delayvalve device I! is connected by way of passage II4 to the vent valvechamber III) and thereby to the brake pipe, the pres sure of fluid insaid diaphragm chamber will reduce with brake pipe pressure. Now whenthe combined pressures of fluid in diaphragm chamber I30 and spring I 31becomes slightly greater than the opposing reduced brake pipe pressurein diaphragm chamber I29, the diaphragm l28 will flex upwardly and causethe delay valve I34 to seat and thereby cut off the communicationbetween chambenliifl and brake cylinder release passage I36.

Fluid under pressure being supplied to the brake cylinder by way ofpassage 65 flows from said passage to the mercury well 48 by way ofpassage passage 52 in the shaft 29 and passage 5| in the beam 2?. Fluidunder pressure thus supplied to the well 48 acts to displace mercuryfrom the well to the chamber 49 by way of the passage in the tubularportion 55 of the beam and passage 66. Now when the weight of mercury inchamber 46 becomes substantially equal to that of the mercury in chamber45, the beam will rock in a counter-clockwise direction to its balancedor service lap position as shown in Fig. '7. It will here be noted thatas the mercury is forced through passage 66 and into chamber 46, the airin the passage and chamber is compressed by the mercury, so that whenthe desired brake cylinder pressure has been obtained, the pressure ofair in chamber 45 together with the pressure of the hydrostatic head ofthe displaced mercury will be substantially equal to brake cylinderpressure. By reason of this, no further flow of mercury to chamber 45can occur, thus the equalizing of the weight carried on the left handend of the beam with that carried on the opposite end and the consequentbalancing of the beam is elfected.

As the beam is moving to service lap position, the lugs I25 of the beamcause the bell crank lever I 2! to rock about the pin l22 in a clockwisedirec tion and as a consequence the arm I 2'! of the lever moves out ofits holding position with relation to the valve 26 of the quick servicevalve device I4 so as to permit the spring I 98 to act to seat the quickservice valve I I5, the valve I I5 when seated cutting off the quickservice flow of fluid from the brake pipe. Further, as the beam ismoving to service lap position it rocks the shaft 29 and thereby the arm49 of the application valve device I2 and arm 42 of the charging controlvalve device I3 in the same direction to the position in which they areshown in Fig. 7. Upon such movement of the arm 49, the valve M is seatedby the action of the spring 153 and the supply of fluid under pressurefrom the supply reservoir I to the brake cylinder is thereby cut olf. Itwill be noted that the movement of the arm 42 is not sufficient to causethe valve seat 52 carried thereby to seat on the valve SI so that thecharging communication between the supply reservoir l and the chamber 38is maintained closed by the action of the spring I59.

In case of leakage of fluid under pressure from the brake cylinder whenthe beam 21 is in lap position, the drop in brake cylinder pressure inwell 48 due to such leakage will permit the displacement of mercury fromthe chamber 46 and passage 56 to well 48. This will of course unbalancethe beam and it will again move to service position and cause the arm 40of the application valve device I2 to operate to unseat the supply valve4i so that fluid under pressure is again supplied from the supplyreservoir I to the brake cylinder. Now when the leakage has beencompensated for by the flow of fluid from the supply reservoir to thebrake cylinder, the beam will be caused to move to its lap position andthe supply of fluid under pressure to the brake cylinder will be cut offin the same manner as before described. It will thus be seen that brakecylinder pressure is maintained against leakage through the operation ofthe beam.

Release following a service application of the brakes When it is desiredto release the brakes following a service application thereof, theoperator moves the brake valve handle I84 to running position as shownin Fig. 3, causing the pinion I82 to rotate in a counter-clockwisedirection. Upon such movement of the pinion and thereby the member I8Ias a whole the screw threads on the member and casing cooperate to movethe member inwardly to increase the pressure of the spring I95 on thefollower I18 and diaphragm H3. The spring upon thus being compressedacts to flex the diaphragm I13 downwardly, the diaphragm acting throughthe medium of the follower stem I80,

appreciable effect upon such reduction. Upon this reduction in thepressure of the fluid in piston chamber ZID, fluid under pressure invalve chamber 2! causes the piston 2, piston stem 252 and thereby theslide valve 2I3 to move in a direction toward the right hand to brakepipe charging position in which the port 225 in the slide valve is inregistration with the brake pipe passage 225. With this communicationestablished, fluid under pressure flows from the main reservoir 2 to thebrake pipe I, and thereby to the brake pipe 5 of the tender and cars ofthe train.

Now when the pressure of fluid in chamber Ht which is in opencommunication with the brake pipe is increased slightly above theopposing pressure of the compressed spring I95, the diaphragm I73 willbe flexed upwardly and will carry with it the follower I18 and stemextension I91 carried by the follower and upon such movement of the stemextension I91 the spring 204 acts to seat the valve 255 and to maintainthe valve I99 in air tight engagement with the extension IS'I duringsuch seating movement. As the valve is approaching its seat it throttlesof? the flow of fluid from the chamber I'IS to the chamber 202 and whenthe rate of flow of fluid past the valve becomes less than the rate offlow of fluid from the valve chamber 2 M to the piston chamber 2 II) byway of the port 221, the pressure of fluid in chamber 2i 8 will beincreased, and since the volume of this chamber and chamber 202 issmall, the pressure in these chambers will quickly equalize with that ofthe pressure of fluid in the main reservoir, so that at the time thevalve Eill is fully closed, the spring 2 I5 acts to move the piston 2 II, stem 2 I2 and thereby the slide valve 2l3 to their cut off positionas shown in Fig. 2.

The initial flow of fluid at high pressure from the main reservoir tothe brake pipe by way of the feed valve device, rapidly increases thebrake pipe pressure on the tender and cars at the head end of the train.This high head of pressure at the front end of the train is desirablefor the reason that it causes a rapid flow of fluid under pressure tothe rear cars of the train and thereby accelerates the release of thebrakes and the charging of the brake equipment on the rear cars.

On the tender and cars of the train, fluid under pressure supplied tothe brake pipe flows to the chamber of the beam 2! by way of brake pipebranch pipe III, quick action valve chamber IIO, passage and pipe II3,chamber 38 in the charging control valve device I3, past valve IBI,passage 5| in the arm 42 of the charging control valve device, passagein the shaft 29 and passage 49 in the beam. The increase in brake pipepressure in chamber 45, occasioned by the flow of fluid from the brakepipe, causes the displacement of mercury from said chamber to the well41. This of course lightens the weight carried by the right hand end ofthe beam. over that carried on the opposite end and as a consequence thebeam will be caused to rock in a counterclockwise direction from servicelap position to either retarded release or back-dump position as shownin Fig. 8 or to normal release position as shown in Fig. 5.

On the tender and cars at the head end of the train where the brake pipepressure will be greatest, there will be a greater amount of mercurydisplaced into the well 41 of the beam as shown in Fig. 8 than will bedisplaced into the corresponding chamber or well on the'cars at the rearend of the train where the rise in brake pipe pressure is slower and thehigh head of pressure is not obtained, as shown in Fig. 5. Due to thedisplacement otmercury from chamber 45 to well 41 by the increase inbrake pipe pressure in the chamber, fluid in well 41 and connectedcontrol chamber is caused to be compressed to substantially the samepressure as the pressure of fluid in chamber 45, the amount of mercurytransferred from. chamber 45 and passage 53 to the well 4'! beingsuflicient to permit the weight of the mercury at the opposite end ofthe beam to cause the beamto start to tilt from lap position towardrelease position.

As the beam is thus being tilted from lap position, the lugs I25 of thebeam cause the bell crank lever I2! to rock in a clockwise direction andas the lever is moved in this direction the arm 24 thereof engages andmoves the plunger I48 inwardly, i. e., in a direction towards the lefthand, unseating the release valve I4I. against the opposition offered bythe spring I52. It will here be noted that the spring I5I does notoppose the operation of the bell crank lever as it is being moved inthis direction until after, as will hereinafter appear, the lever ismoved beyond release position. I

On the cars at the rear end of the train where there is no high head ofpressure and the brake pipe pressure is increased more gradually than onthe cars at the head end of the train, the a beam 2'? will come to astop in release position as shown in Fig. 5 when the fluid in thecontrol chamber 44 is compressed by the mercury to a pressuresubstantially equal to the brake pipe pressure in chamber 45. g

From an inspection of Fig. 5 it will be seen that when the beam 2'? isin its normal release position and the release valve I4I isin full openposition, the retarded release valve I43 is not seated on the seat ribI43, so that fluid under pressure may be released from the brakecylinder at the normal rate.

When, in charging the brake pipe as just described, the brake pipepressure in diaphragm chamber I29 of the brake cylinder release delayvalve device I i has been increased slightly in excess of brake cylinderpressure in diaphragm chamber I30 the diaphragm I28 will be flexeddownwardly, causing the delay valve I35 to be unseated, so that fluidunder pressure is now released from the brake cylinder by way of pipeand passage I3I, diaphragm chamber I35, past the fluted follower stemI33 and unseated delay valve I34, delay valve chamber I35, passage I36,past the retarded release valve I40, valve chamber I42, past theunseated release valve MI and its fluted stem I43, chamber I45, pipe I46and retainer valve device I 41.

On the tender and cars at the head end of the train where the brake pipepressure is temporarily greater than on the cars at the rear end of thetrain, there will be a greater amount, of mercury displaced from passage53 into well 41 so that the beam 2] will not come to a stop in normalrelease position but will continue to move beyond this position towardretarded release po sition. As the beam: is being moved from releaseposition the weighted end 89 of the arm 86 operatively engages theupwardly extending portion 85 of the arm 85 pivotally'carried by thebeam and thereby maintains the arm and vent valve I8 stationary so thatwhile the beam continues to tilt, the seat tor the valve willbe movedupwardly out of sealing engagement with the valve, thus permitting fluidunder pressure tobe vented from the control chamber to the atmosphere byway of the fluted stem of the valve. This reduction in control chamberpressure permits the rapid displacement of more mercury from the passage53 to well 4'! so that the weight of the mercury in chamber 45 causesthe beam to tilt to retarded release position as shown in Fig. 8, inwhich position, the beam is stopped by the engagement of the stop 83 onthe casing with the stop 82 on the beam. Just before the beam reachesits retarded release position the projecting portion 85 of the arm 88moves with the beam to the left hand side of the longitudinal centerline of the arm 85 as shown in Fig. 8, so that the spring 84 acts toseat the valve I8 and thereby cut off the flow of fluid from controlchamber 44 to the atmosphere.

As the beam is being tilted from its normal release position to itsretarded release position as just described, the bell crank lever I2! isrocked further in a clockwise direction, so that the arm I25 thereof,acting through the medium of the plunger I49 seats the retarded releasevalve I48 on the seat rib I43, so that fluid under pressure is releasedfrom the brake cylinder at a retarded rate by way of the flowrestricting port I 44 which connects the passage I36 and valve chamberI42. It will here be noted that the plunger I49, as it is thus moved toretarded release position, compresses the heavy coil spring I5I. Thepurpose of this spring is two-fold, first to stabilize the beam againstaccidental movement to retarded release position and secondly to effectthe operation of the beam from retarded release position to normalrelease position as will hereinafter more fully appear.

As the beam is being tilted from normal release position to retardedrelease position the shaft 29 and thereby the arm 42 of the chargingcontrol valve device I3 is rocked in the same direction. Upon suchmovement of the arm 42 the valve seat 52 carried thereby is moved intoseating engagement with the valve I8I and then acts through the mediumof said valve and its fluted stem I60 to unseat the back-dump valve 43against the opposing pressures of the spring I59. With the valve 43unseated fluid under pressure flows from the supply reservoir to thebrake pipe by way of pipe and passage I5, passage and pipe I55, the flowrestricting passage in the choke plug I55, passage I51, past the ballcheck valve I58, valve chamber I54, past valve 43 and its stem I56,chamber 38 in the charging control valve device, passage and pipe H3,quick action vent valve chamber H8 and branch pipe III. With the valveseat 52 in engagement with the valve IBI the flow of fluid from thechamber 33 of the charging control valve device I3 and therefore fromthe brake pipe to the chamber 45 in the beam is cut off, so that therecan be no flow of brake pipe fluid from the chamber 45 and passage 53through the control chamber 44 and supply reservoir I. By reason of thisa greater amount of fluid under pressure will flow towards the rear endof the train than would otherwise be the case.

Since the well 48 is in communication with the brake cylinder passage59, the pressure of fluid in the well will reduce with brake cylinderpressure and, as the pressure in this chamber reduces, the mercury willbe displaced from chamber 46 and passage 66 into the well 48. Now whenthe brake cylinder pressure has been reduced to some low degree,sufiicient mercury will have been returned to well 48 to so conditionthe beam that the spring I 5I acting through the medium of the plungerI49, arm I24 of the bell crank lever I2I and lug I26 of the beam, willcause the beam to tilt from retarded release position to normal releaseposition. It will here be noted that upon such movement of the beam thevalve seat 52 of the charging control valve device I3 is moved away fromthe valve I6I so that communication is now established between thechamber 38 and chamber 45 of the beam, so that the control chamber 44and supply reservoir 1 are now recharged in the same manner as has beendescribed in connection with the initial charging of the equipment.

Emergency application of the brakes When it is desired to effect anemergency application of the brakes the operator moves the brake Valvehandle I84 to emergency position which causes the member I8I to rotatein a clockwise direction and upon such movement of the member the screwthreads of the member and cap I'I2 cooperate to move the member upwardlyinto engagement with he pin I96 in the follower stem I19 and, throughthe medium of the pin, to shift the stem and thereby the follower I'I8,diaphragm I'I3, stem I80 and stem extension I9? upwardly a sufficientdistance that the valve seat on the extension I9? is out of engagementwith the valve I99. With the seat moved away from the valve I99 fluidunder pressure is vented from the brake pipe by way of pipe and passageI'I'I, diaphragm chamber I16, passage I98 in stem I19, chamber I14 andpassage H5.

The handle I84 as it is thus moved, not only actuates the member I8! asjust described, but also rotates the emergency valve I9I to emergencyposition as shown in Fig. 4, in which position, fluid at main reservoirpressure in chamber I92 flows through a port 258 in the valve andpassage and pipe 2I'I to the quick action piston chamber 2H3 of the ventvalve device 5 on the locomotive. Fluid under pressure thus supplied tothe chamber 2I8 causes the piston 2I8 and thereby the quick action ventvalve 220 to move downwardly, the valve being moved away from its seatrib so as to permit fluid under pressure to flow from the brake pipe tothe atmosphere by way of branch pipe and passage 222, valve chamber 22!,past the unseated vent valve 228 and its fluted stem 2 I9 and passage223.

It will here be noted that since the member I8I acting through themedium of the pin I93 and follower assembly positively holds the stemextension I91 out of engagement with the valve 599 when an emergencyapplication of the brakes is being efiecte'd, the valve 2Ell will beheld seated by the action of the spring 284', so that there will be nodanger of the feed valve device 4 operating to supply fluid underpressure from the main reservoir to the brake pipe, thus insuringagainst the loss of main reservoir pressure by way of the brake pipe andquick action vent valve device 5.

The rapid reduction in brake pipe pressure which is produced by quicklyventing fluid under pressure from the brake pipe to the atmosphere bymeans of the quick action vent valve device 5 on the locomotive iseffective in the chamber 45 of the beam 21. Since the pressure of fluidin chamber 45 is quickly reduced, the pressure of fluid in controlchamber 44 will quickly displace the mercury from well 41 to the passage53 and chamber 45. This will cause the beam 21 to quickly tilt in aclockwise direction to its emergency position as shown in Fig. 9. Whenthe level of the mercury in well 47 reaches the junction point 223between the passage 53 and well, the member 5'! will obviously be seatedon the rib 59 of the beam and as a consequence fluid under pressure fromthe control chamber 44 will flow through the restricted port 58 in themember, past the junction point 228 and then bubble through the mercuryin passage 53 and chamber 5 to the passage 59 and consequently to thebrake pipe which is open to the atmosphere by way of the vent valvedevice 5. The purpose of this member 5'! and the flow re-- strictingport 53 therein is to prevent the pressure of fluid in the controlchamber from forcing the mercury from the chamber 15 to the passages andchambers leading to the brake pipe when the sudden reduction in brakepipe pressure is effected.

As the beam 27 is being tilted in effecting an emergency application,the operation of the several parts or" the equipment will besubstantially the same as in effecting a service application of thebrakes until such time as the beam tilts from service position toemergency position. This movement of the beam from service position toemergency position causes the bell crank lever i2! to move in acounter-clockwise direction a sufficient distance for the arm l2!thereof to seat the valve i261 against the opposing pressure of thespring M3, the valve in its seated position cutting off communicationfrom the passage I05 leading from the qu ck action piston chamber H33and the atmosphere. With this communication closed, fluid under pressureflowing from the brake pipe to the chamber m3, by way or" the open quickservice valve H5, causes the quick action piston to move in a directiontoward the right hand to unseat the quick action Valve its against theopposing pressure of the spring H2. With the valve Ills unseated fluidunder pressure is quickly vented locally from the brake pipe andconsequently from the chamber of the beam 2?.

Now when the brake cylinder pressure has been increased to the pressurefor which the equipment is adjusted to produce in emergency, suiiicientmercury will have been displaced from well 38 to chamber 416 to causethe beam 21 to tilt iromemergency position to lap position as shown inFig. 7.

When the beam 2'] is in emergency position, and the brake pipe pressurehas been reduced to atmospheric pressure, the control chamber will notbe reduced to atmospheric pressure for the reason that as the controlchamber pressure reduces the weight of the mercury in chamber 3.? andpassage 53 causes the mercury to flow back from the junction point 228to the bottom of the well 37, thus bottling up fluid in the well at apressure sufiicient to prevent the gravitational flow of mercury fromthe chamber to the well.

It will here to noted that the maximum brake cylinder pressureobtainable in effecting an emergency application of the brakes isdependent upon the amount of mercury required in chamber 46 and passage6'53 to balance the weight of mercury contained in passage 53 andchamber 55 and not upon the volume of the supply reservoir 2, so thatthis reservoir may be made large enough to maintain brake cylinderpressure against leakage as hereinbefore described and to assist inaccelerating the release of the brakes.

When the beam 27 tilts from emergency position to lap position the bellcrank lever lZI will be moved by the beam to permit the quick servicevalve il5 to be seated and the valve I20 to be unseated by the action ofthe spring H8. With the valve E20 unseated fluid under pressure isvented from the quick action piston chamber I03 so that the spring H2acts to seat the quick action vent valve H19 and thereby cut offcommunication from the brake pipe to the atmosphere.

Release of the brakes following an emergency application When it isdesired to release the brakes following an emergency application thebrake valve handle I8& is moved from emergency position to runningposition and, as the handle is thus moved, the emergency valve l9l ismoved to a corresponding position in which fluid under pressure isvented from the quick action piston chamber 21s to the atmosphere by Wayof pipe and passage 21?, a cavity 251 in the valve l9! and a passage252. With the chamber 2H3 thus vented the spring 224 acts to seat thevent valve 220 to close off the communication from the brake pipe to thepassage 223 leading to the atmosphere. With the handle in this positionthe spring'iSE, due to the downward movement of the member it?! actsthrough the medium of the follower I78, follower stem Hi0 and followerstem l= extension I97 to unseat the valve 2%. With the valve 20!unseated fluid under pressure is vented from the feed valve pistonchamber 219 to the chamber lit and consequently to the brake pipe, bothof which are at atmospheric pressure, causing the feed valve device tooperate to supply fluid under pressure from the main reservoir to thebrake pipe. Upon thus increasing brake pipe pressure the brake valvedevice will operate to so control feed valve device as to limit thebrake cylinder pressure to that which it is desired to carry in theequipment in substantially the same manner as has been described inconnection with releasing the brakes following a service application ofthe brakes.

As the brake pipe pressure is being increased, the beam 2'! will betilted to either its retarded release position or to its normal releaseposition as the case may be and the brakes will be released insubstantially the same manner as they are released following a serviceapplication. There is however one difference in releasing the brakesfollowing an emergency application and that is the sensitivity of thebeam Z'l to movement to release position is increased. In thisconnection it will be noted that since the pressure of the controlchamber M is reduced during an emergency application to almostatmospheric pressure only a slight increase in brake pipe pressure isrequired to displace suflicient mercury from the chamber 45 into thewell ll to cause the beam to rock to either of its release positions.When the delay valve device I? is employed the rapid transmission of thereleasing action of the beam 2? and the several parts associatedtherewith will not accelerate the release of the brakes, but where allof the cars of a rain are equipped with my brake equipment the delayvalve device ll will be omitted so that the accelerated release movementof the beam 2? will result in an accelerated transmission or" therelease of the brakes throughout a long train. This is of course verydesirable in that it makes it possible to get the train under way inless time than would otherwise be the case.

Limited service application of the brakes In order to limit the degreeof brake application, the brake pipe pressure is only reduced an amountsufficient to efiect the desired service application, and this isadapted to be accomplished by moving the brake valve handle I84 to theposition in the application and release zone which corresponds to thedegree of braking desired. The brake valve device now functionsautomatically to limit the reduction in brake pipe pressure according tothe position of the handle as will be understood from the foregoingdescription. When the usual well known type of engineers automatic brakevalve device is employed the limited reduction in brake pipe pressureobtained by moving the brake valve handle from release position toservice position until the desired reduction is effected and then to lapposition in which the flow of fluid from the brake pipe is cut off.

This reduction in brake pipe pressure permits the pressure of fluid incontrol chamber 44 of the beam 21 to displace a proportionate amount ofmercury from the well 41 to the chamber 45, causing the beam to move toits service position to effect the supply of fluid under pressure to thebrake cylinder. Now as the pressure of fluid in the brake cylinder andconsequently in the well 58 of the beam is increasing, mercury isdisplaced, due to the increase in fluid pressure in well :18, to passage66 and chamber 46. When the weight of mercury in passage 66 and well 68is sufiicient to effect the balance of the beam, the beam moves to lapposition, efiecting the operation of the application valve device l2 tocut off the flow of fluid from the supply reservoir to the brakecylinder.

If, after a limited application of the brakes has been effected, it isdesired to increase the brake cylinder pressure, a further reduction inbrake pipe pressure is effected through the medium of the brake valvedevice, which reduction causes the beam 2? to move from lap position toservice position, causing the application valve device to again operateto supply fluid under pressure from the supply reservoir to the brakecylinder. When the desired brake cylinder pressure is obtained the beamwill again move to lap position, causing the application valve device tooperate to out 01f the flow of fluid from the supply reservoir to thebrake cylinder,

From this it will be apparent that it is possible to obtain the servicebraking pressure up to full service in small increments or stagesespecially when the brake valve device shown in Fig. 2 is employed.

Description of the modification shown in Fig. 11

As long as there is a possibility of mixed brake equipments beingemployed in a train the brake cylinder release delay valve device I?will be employed, but when there is no longer such a possibility, thebrake cylinder release delay valve and the mechanism for controlling itsoperation may be omitted and the passage H4 closed by a plug 215 asshown in Fig. 11. When this is done there will be no delay in effectingthe release of the brake and the release of the brakes will becontrolled only by the operation of the brake cylinder release valvedevice [8. It will be apparent that with the delay valve omitted and thepassage I I closed as just described, either the graduated release ordirect release of the brakes may be effected, the type of release beingdependent upon the operation of the brake valve device.

The other operations of the apparatus may be substantially the same asthose described in connection with the apparatus when the delay valve isemployed.

Description of the modification shown in Fig. 12

In Fig. 12 it is shown how the apparatus may be modified for use inshort trains, such as passenger trains, where there is no danger fromthe run in or closing of the train slack. In this modification the brakecylinder build-up control valve M has been omitted, so that the build upof brake cylinder pressure will be at an uninterruptcd rate instead ofat three different rates as is the case when the build-up control valvedevice is employed.

Since, on a short train, the run out of slack will not be severe theretarded release feature is omitted from the apparatus shown in Fig. 12,the release of the brakes being controlled by a release valve mechanismcomprising a release valve piston 27% and a pilot release valve 217which is adapted to be controlled by the bell-crank lever i2l. The valvepiston 216 has mounted in one end thereof an annular gasket 218 which isadapted to engage an annular seat rib 219 to cut off directcommunication from a chamber 280 to an exhaust passage 28! leading tothe atmosphere, which chamber is connected to the brake cylinder passageIN, the supply passage 98 and. the control passage 63. The other end ofthe valve piston is provided with a valve seat 282 upon which the pilotValve 2'l'l is adapted to seat, said pilot valve having a fluted stem283 which extends through a central bore in the release valve and whichat its end is adapted to be operatively engaged by the arm I24 of thebell-crank lever I21.

The pilot valve 271 is contained in a chamber 28d which is connectedthrough a flow restricting passage 2% to the chamber 288. Also containedin this chamber are coil springs 236 and 1 :87, the spring 286 tendingat all times to seat the pilot valve Z'l'l and the spring 281 tending atall times to move the valve piston toward the right hand to its seatedposition.

With the tiltable beam 21 in release position as shown, the arm E24 ofthe bell-crank lever [2| maintains the pilot valve 217 unseated againstthe opposing pressure of the spring 285 so that the chamber 286 andconsequently the brake cylinder and other chambers connected therewithare open to the atmosphere by way of passage 285, valve chamber 284, thecentral bore in the valve piston 276 and passage 28!. With the chamber280 at atmospheric pressure the spring 28'! acting on the valve pistonmaintains the gasket 218 in sealing engagement with the seat rib 279.

When, to effect an application of the brakes, the beam 27 is rocked in aclockwise direction, the bell-crank is caused to rock in the oppositedirection and thereby permits the spring 286 to act to seat the pilotvalve 211. After this valve is seated fluid under pressure is suppliedto the rake cylinder in substantially the same manner as hereinbeforedescribed in connection with the apparatus shown in Figs. to inclusive.

Now when the beam 21 is rocked in a counterclockwise direction to effectthe release of the brakes the arm I24 of the bell-crank lever l2lengages the pilot valve stem 283 and moves the pilot valve from thevalve seat 282. With the valve

